Moving armature receiver

Abstract

A compact moving armature receiver where the diaphragm element is positioned in the air gap of the magnet assembly and where a suspension element is provided for defining the front chamber, the suspension element has a stiffness of at the most 500 N/m. The suspension element and the diaphragm element may be made from the same sheet of a foil, and the suspension element may be formed by bent or curved peripheral parts of the foil.

1. A receiver comprising a housing having therein:
 a permanent magnet assembly generating a magnetic field in an air gap, 
 an electrically conductive drive coil comprising a coil tunnel, 
 a sound output, 
 a magnetically permeable armature assembly extending in a first direction through the air gap and the coil tunnel, 
 a suspension element having a stiffness of at the most 500 N/m, and 
 a diaphragm element for producing sound, extending in the air gap, and being operatively attached to the suspension element, 
 wherein the housing has a first and a second chamber defined at least by opposite sides of the diaphragm element and the suspension element and wherein the sound output extends between the first chamber and the surroundings of the receiver. 
 
     
     
       2. A receiver according to  claim 1 , wherein the armature assembly has a stiffness of at least 600N/m. 
     
     
       3. A receiver according to  claim 1 , wherein the suspension element provides a sealing between edges or circumferential parts of the diaphragm element and an internal surface of the housing. 
     
     
       4. A receiver according to  claim 1 , wherein the diaphragm element and the suspension element comprises a film, the diaphragm element being formed at least partly by an at least substantially planar central part of the film, and the suspension element being formed at least partly by one or more peripheral, bent or curved parts of the film. 
     
     
       5. A receiver according to  claim 4 , wherein the first portion of the armature assembly is fixed to the central part of the film. 
     
     
       6. A receiver according to  claim 1 , wherein the armature assembly has a part forming at least part of the diaphragm element, extending in the air gap, and having a predetermined width, the suspension element being provided at peripheral portions of the part of the armature assembly. 
     
     
       7. A receiver according to  claim 1 , wherein the armature assembly is hingedly or bendably fixed at an end positioned at one end of the coil tunnel, the air gap being positioned at another end of the coil tunnel. 
     
     
       8. A receiver according to  claim 1 , wherein the magnet assembly comprises a permanent magnet positioned in the first chamber. 
     
     
       9. A receiver according to  claim 1 , wherein the suspension element provides an acoustical seal between peripheral portions of the diaphragm element and an inner surface of the housing. 
     
     
       10. A receiver according to  claim 1 , wherein the diaphragm element defines a first plane, and wherein the suspension element forms a seal between peripheral portions of the diaphragm and parts of the inner surface of the housing at least substantially in the first plane. 
     
     
       11. A receiver according to  claim 1 , wherein the diaphragm element defines a first plane, and wherein the suspension element forms a seal between peripheral portions of the diaphragm and parts of the inner surface of the housing extending at least substantially parallel to the first plane. 
     
     
       12. A receiver according to  claim 1 , wherein the housing has a largest dimension, perpendicular to a plane defined by the diaphragm assembly, of no more than 1.9 mm. 
     
     
       13. A receiver according to  claim 1 , wherein the housing, in a plane perpendicular to the first direction, has a width in a plane defined by the diaphragm assembly and a thickness perpendicular thereto, the width being between 1 and 10 times the thickness.